Ardour supports three common timecode formats: LTC, @@ -16,7 +14,6 @@ translate timecode. e.g create LTC timecode from incoming MTC.
-@@ -83,6 +80,7 @@
The MTC generator has no options. Ardour sends full MTC frames whenever the transport is relocated or changes state (start/stop). @@ -91,17 +89,20 @@
The level of the LTC generator output signal can be configured in the Preferences > Transport dialog. By default it is set to -18 dBFS, which corresponds to 0dBu in an EBU calibrated system.
+The LTC generator has an additional option to keep sending timecode even when the transport is stopped. This mode is intended to drive analog tape machines which unspool the tape if no LTC timecode is received.
+LTC is sent regardless of Ardour's transport speed. It is accurately generated even for very slow speeds (<5%) and only limited by the @@ -111,8 +112,8 @@ for high speeds.
-The timecode source can be switched with the button just right of Ardour's main clock. By default it is set to Edit > Preferences > Transport.
+When Ardour is chasing (synchronizing to) an external timecode source, the following cases need to be distinguished:
+and
+In both cases the first option is preferred: clock sync + same FPS setting.
If the frames-per-second do not match, Ardour can either re-calculate and map the frames, or the configured FPS (Session > @@ -147,6 +154,7 @@ > Preferences > Transport > Match session video frame rate to external timecode.
+When enabled, the session video frame rate will be changed to match that of the selected external timecode source. When disabled, the session video @@ -155,6 +163,7 @@ flash red, and Ardour will convert between the external timecode standard and the session standard.
+29.97 drop-frame timecode is another corner case. While the SMPTE 12M-1999 specifies 29.97df as 30000/1001 frames per second, not all hardware devices @@ -173,6 +182,7 @@
As described in the On Clock and Time @@ -180,30 +190,29 @@ source is not in sample-sync with the audio hardware (and JACK), Ardour needs to run at varispeed to adjust for the discrepancy.
+The checkbox External timecode is sync locked allows to select the behavior according to the setup. When enabled, it indicates that the selected external timecode source shares sync (Black & Burst, Wordclock, etc) with the audio interface.
+In other words: if enabled, Ardour will only perform initial synchronization and keep playing at speed 1.0 instead of vari-speed adjusting to compensate for drift.
-- Note that vari-speed is unavailable when recording in Ardour, and all - tracking happens at speed 1.0. So in order to record in sync with - external timecode it must be sample-locked or it will drift over time. -
MIDI Clock is not a timecode format but tempo-based time. The absolute reference point is expressed as beats-per-minute and Bar, Beat and Tick. There is no concept of sample-locking for MIDI clock signals. Ardour will vari-speed if necessary to chase the incoming signal.
+
Note that the MIDI Clock source must be connected to the
ardour:MIDI clock in port.
@@ -271,23 +280,26 @@
When Ardour is chasing MTC, the main transport clock will display the - received Timecode as well as the delta between the incoming signal and + received timecode as well as the delta between the incoming signal and Ardour's transport position.
- When slaved to jack, Ardour's transport will be identical to - JACK-transport. As opposed to other slaves, Ardour can be used to control - the JACK transport states (stopped/rolling). No port connections need to - be made for jack-transport to work. + When slaved to jack, Ardour's transport will be identical to JACK Transport. + As opposed to other slaves, Ardour can be used to control the JACK transport + states (stopped/rolling). No port connections need to be made for + JACK Transport to work.
+- JACK-transport does not support vari-speed, nor offsets. Ardour does not + JACK Transport does not support vari-speed, nor offsets. Ardour does not chase the timecode but is always in perfect sample-sync with it.
+- JACK-transport also includes temp-based-time information in Bar:Beats:Ticks + JACK Transport also includes temp-based time information in Bar:Beats:Ticks and beats-per-minute. However, only one JACK application can provide this information at a given time. The checkbox Session > Properties > JACK Time Master diff --git a/include/transport-bar.html b/include/transport-bar.html index da7155b0..134b3958 100644 --- a/include/transport-bar.html +++ b/include/transport-bar.html @@ -61,9 +61,9 @@ allows to temporarily scrub through the audio quickly. The slider decides the playback speed: the further from the center it is set, the faster the playback will scrub in both directions. The range of - this acceleration can be set by right - clicking the control and setting the multiplier, between 1.5 - (± 150%) and 8 (± 800%). + this acceleration can be set by right-clicking + the control and setting the multiplier, either 1.5 (± 150%) or 2 + (± 200%).
- On the left of the slider is the positional sync button (which might show Internal, - or MTC or several other values), than can be used to control whether or not the - transport position and start is controlled by Ardour, or by an external positional - synchronization source, such as MIDI Time Code (MTC), Linear Time Code (LTC) or JACK - (see Timecode Generators and Slaves). + On the left of the slider is the positional sync button (which might show + Internal, or MTC or several other values), than can be + used to control whether or not the transport position and start is controlled + by Ardour, or by an external positional synchronization source, such as MIDI + Time Code (MTC), Linear Time Code (LTC) or JACK (see + Timecode Generators and Slaves).